Three-dimensional forming apparatus and three-dimensional forming method

ABSTRACT

A three-dimensional forming apparatus includes: a stage; a material supply unit that supplies the stage with a sintered material including metal powder and a binder, a head unit that includes an energy radiation unit supplying energy capable of sintering the sintered material to the sintered material supplied by the material supply unit, a head base that holds a plurality of the head units, and a driving unit that is capable of three-dimensionally moving the head base relative to the stage.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of U.S. patent application Ser. No.15/163,287, filed May 24, 2016, which claims priority to Japanese PatentApplication No. 2015-106177, filed May 26, 2015. The foregoingapplications are hereby incorporated by reference in their entirety.

BACKGROUND 1. Technical Field

The present invention relates to a three-dimensional forming apparatusand a three-dimensional forming method.

2. Related Art

In the related art, a method described in JP-A-2008-184622 is disclosedas a manufacturing method of simply forming a three-dimensional shapeusing a metal material. The three-dimensional fabricated objectmanufacturing method disclosed in JP-A-2008-184622 is used to form ametal paste, which includes metal powder, a solvent, and an adhesionenhancer in a raw material, in material layers of a layered state. Then,metal sintered layers or metal melted layers are formed by radiating alight beam to material layers in the layered state and the sinteredlayers or the melted layers are stacked by repeating the forming of thematerial layers and the radiation of the light beam, so that a desiredthree-dimensional fabricated object can be obtained.

A three-dimensional fabricated object is suggested to be formed bysupplying a metal powder using a powder metal buildup nozzle capable ofbuilding up a (three-dimensional) form, as disclosed inJP-A-2005-219060, or a powder supply nozzle capable of performingbuildup and welding, as disclosed in JP-A-2013-75308, and by melting andsolidifying the supplied metal powder with a laser.

A three-dimensional fabricated object can be formed by forming andstacking sintered layers to material layers, as in a method disclosed inJP-A-2008-184622, or a three-dimensional fabricated object can be formedby repeating buildup, as in methods disclosed in JP-A-2005-219060 andJP-A-2013-75308. These methods are methods of forming one single layerwhich forms a three-dimensional fabricated object and stacking thesingle layers. In a case in which the single layer of one configurationin a three-dimensional fabricated object is formed, laser radiation isscanned to draw a trajectory so that a formed sintered portion is filledin the case of JP-A-2008-184622 and a nozzle is moved along a trajectorydrawn so that the shape of a sintered portion is filled in the cases ofJP-A-2005-219060 and JP-A-2013-75308. That is, to draw theabove-described trajectory by relatively moving a table for forming thethree-dimensional fabricated object and a laser radiation device or thenozzle, a device driving unit necessarily performs minute control forthe relative movement.

A time taken to form the above-described single layer increases as thelength of the trajectory is longer, that is, the area of the sinteredportion is greater. Accordingly, to improve productivity, a scanningspeed of the laser radiation or a movement speed of the nozzle isnecessarily increased. However, when an output of the laser is not high,there is a concern of a sintering fault or a melting fault occurring.

SUMMARY

An advantage of some aspects of the invention is that it provides athree-dimensional forming apparatus with high productivity by driving aplurality of energy supply units synchronously with a simpleconfiguration.

The invention can be implemented as the following forms or applicationexamples.

Application Example 1

A three-dimensional forming apparatus according to this applicationexample includes: a stage; a material supply unit that supplies thestage with a sintered material including metal powder and a binder; ahead unit that includes an energy radiation unit supplying energycapable of sintering the sintered material to the sintered materialsupplied by the material supply unit; a head base that holds a pluralityof the head units; and a driving unit that is capable ofthree-dimensionally moving the head base relative to the stage.

A sintered portion corresponding to one energy radiation unit is formedalong one path of the relative movement of the head base relative to thestage by energy radiated from the energy radiation unit included in onehead unit. Accordingly, the three-dimensional forming apparatusaccording to the application example includes the plurality of headunits in the head base, and thus a plurality of sintered portions can beformed along one path of the head base. Accordingly, it is possible toshorten a relative movement path length between the head base and thestage along which a desired sintered region is formed, and thus it ispossible to obtain the three-dimensional forming apparatus with highproductivity.

Application Example 2

A three-dimensional forming apparatus according to this applicationexample includes: a stage; a material supply unit that includes amaterial ejection unit supplying a sintered material including metalpowder and a binder to the stage; an energy radiation unit that suppliesenergy capable of sintering the sintered material to the sinteredmaterial supplied by the material supply unit; a head base that holds aplurality of head units in which the material ejection unit and theenergy radiation unit are held; and a driving unit that is capable ofthree-dimensionally moving the head base relative to the stage.

A sintered portion corresponding to one head unit is formed along onepath of the relative movement of the head base relative to the stage byenergy radiated from the energy radiation unit to the sintered materialsupplied from the material ejection unit included in one head unit.Accordingly, the three-dimensional forming apparatus according to theapplication example includes the plurality of head units in the headbase, and thus a plurality of sintered portions can be formed along onepath of the head base. Accordingly, it is possible to shorten a relativemovement path length between the head base and the stage along which adesired sintered region is formed, and thus it is possible to obtain thethree-dimensional forming apparatus with high productivity.

In the three-dimensional forming apparatus according to the applicationexample, the amount of sintered material necessary in a region in whichthe shape of a three-dimensional fabricated object to be formed isformed is supplied and the energy is supplied from the energy radiationunit to the supplied sintered material. Therefore, a loss of thesupplied material and a loss of the supplied energy are reduced.

Application Example 3

In the application example described above, of the plurality of materialsupply units, the material supply unit including the material ejectionunit held in at least one of the head units may accommodate thedifferent sintered material from the other material supply units.

According to this application example, the material supply unitsupplying the sintered material for each different composition can beincluded. Thus, the material can be supplied from each material supplyunit of each composition, and thus different materials can be sinteredor melted by the energy radiation units. Thus, it is possible to easilyform the fabricated object formed of the materials of two or more kindsof compositions.

Application Example 4

In the application example described above, the energy may be a laser.

According to this application example, the radiation of the energy canbe focused on a supply material which is a target, and thus athree-dimensional fabricated object with good quality can be formed. Forexample, a radiated energy amount (power or a scanning speed) can beeasily controlled according to a kind of sintered material, and thus thethree-dimensional fabricated object with desired quality can beobtained.

Application Example 5

A three-dimensional forming method according to this application exampleincludes: supplying a stage with a sintered material including metalpowder and a binder; forming a single layer by moving a head base thatholds a plurality of head units including an energy radiation unit thatsupplies energy capable of sintering the sintered material relative tothe stage, supplying the energy to the sintered material, and sinteringthe sintered material; and forming a second layer in the forming of thesingle layer by stacking the second layer on a first single layer formedin the forming of the single layer. The forming of the second layer isrepeated a predetermined number of times.

A sintered portion corresponding to one energy radiation unit is formedalong one path of the relative movement of the head base relative to thestage by energy radiated from the energy radiation unit included in onehead unit. Accordingly, in the three-dimensional forming methodaccording to the application example, the three-dimensional formingapparatus including the plurality of head units in the head base isused, and thus a plurality of sintered portions can be formed along onepath of the head base. Accordingly, it is possible to shorten a relativemovement path length between the head base and the stage along which adesired sintered region is formed, and thus it is possible to obtain thethree-dimensional forming method with high productivity.

In the application example, the “first single layer” and the “secondsingle layer” do not mean the first and second layers of stacked singlelayers. A single layer in the stack lower portion of repeatedly stackedsingle layers is referred to as the “first single layer” and a singlelayer stacked on the first single layer is referred to as the “secondsingle layer”.

Application Example 6

A three-dimensional forming method according to this application exampleincludes: forming a single layer, the forming of the single layerincluding ejecting a sintered material including metal powder and abinder from a material ejection unit to a stage by moving, relative tothe stage, a head base that holds a plurality of head units holding thematerial ejection unit included in a material supply unit that suppliesthe sintered material to the stage and an energy radiation unitsupplying energy capable of sintering the sintered material to thesintered material supplied by the material supply unit, and includingsupplying the energy to the sintered material ejected in the ejecting ofthe sintered material and sintering the sintered material; and forming asecond single layer in the forming of the single layer by stacking thesecond single layer on the first single layer formed in the forming ofthe single layer. The forming of the second layer is repeated apredetermined number of times.

A sintered portion corresponding to one head unit is formed along onepath of the relative movement of the head base relative to the stage byenergy radiated from the energy radiation unit to the sintered materialsupplied from the material ejection unit included in one head unit.Accordingly, in the three-dimensional forming method according to theapplication example, the three-dimensional forming apparatus includingthe plurality of head units in the head base can be used, and thus aplurality of sintered portions can be formed along one path of the headbase. Accordingly, it is possible to shorten a relative movement pathlength between the head base and the stage along which a desiredsintered region is formed, and thus it is possible to obtain thethree-dimensional forming method with high productivity.

In the application example, the “first single layer” and the “secondsingle layer” do not mean the first and second layers of stacked singlelayers. A single layer in the stack lower portion of repeatedly stackedsingle layers is referred to as the “first single layer” and a singlelayer stacked on the first single layer is referred to as the “secondsingle layer”.

Application Example 7

In the application example described above, of the plurality of materialsupply units, the material supply unit including the material ejectionunit held in at least one of the head units may accommodate thedifferent sintered material from the other material supply units.

According to this application example, the material supply unitsupplying the sintered material for each different composition can beincluded. Thus, the material can be supplied from each material supplyunit of each composition, and thus different materials can be sinteredor melted by the energy radiation units. Thus, it is possible to easilyform the fabricated object formed of the materials of two or more kindsof compositions.

Application Example 8

In the application example described above, the energy may be a laser.

According to this application example, the radiation of the energy canbe focused on a supply material which is a target, and thus athree-dimensional fabricated object with good quality can be formed. Forexample, a radiated energy amount (power or a scanning speed) can beeasily controlled according to a kind of sintered material, and thus thethree-dimensional fabricated object with desired quality can beobtained.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described with reference to the accompanyingdrawings, wherein like numbers reference like elements.

FIG. 1 is a schematic diagram illustrating the configuration of athree-dimensional forming apparatus according to a first embodiment.

FIGS. 2A and 2B are diagrams illustrating an example of a holding formof a plurality of head units held in a head base according to the firstembodiment, FIG. 2A is an external diagram illustrating the head base ina direction indicated by an arrow A illustrated in FIG. 1, and FIG. 2Bis a schematic sectional view taken along the line B-B′ illustrated inFIG. 2A.

FIGS. 3A to 3E are plan views conceptually illustrating a relationbetween disposition of the head units and form shapes of sinteredportions according to the first embodiment.

FIG. 4A is a schematic diagram illustrating the configuration of athree-dimensional forming apparatus according to a second embodiment andFIG. 4B is an enlarged view of a portion C illustrated in FIG. 4A.

FIG. 5 is an external diagram illustrating the head base in a directionindicated by an arrow D illustrated in FIG. 4B according to the secondembodiment.

FIG. 6 is a sectional view taken along the line E-E′ illustrated in FIG.5.

FIGS. 7A to 7C are plan views conceptually illustrating a relationbetween disposition of the head units and form shapes of sinteredportions according to the second embodiment.

FIGS. 8D and 8E are plan views conceptually illustrating a relationbetween disposition of the head units and form shapes of sinteredportions according to the second embodiment.

FIG. 9 is a plan view conceptually illustrating the relation betweendisposition of the head units and the form shapes of the sinteredportions according to the second embodiment.

FIGS. 10A and 10B are schematic diagrams illustrating another example ofthe disposition of the head units disposed in the head base.

FIG. 11 is a flowchart illustrating a three-dimensional forming methodaccording to a third embodiment.

FIG. 12 is a schematic diagram illustrating the configuration of a greensheet forming apparatus according to the third embodiment.

FIGS. 13A and 13B are schematic plan views illustrating steps of thethree-dimensional forming method according to the third embodiment andare sectional views taken along the line F-F′ illustrating in theschematic plan views.

FIGS. 14C and 14D are schematic plan views illustrating steps of thethree-dimensional forming method according to the third embodiment andare sectional views taken along the line F-F′ illustrating in theschematic plan views.

FIGS. 15E and 15F are external perspective views illustrating steps ofthe three-dimensional forming method according to the third embodimentand are schematic sectional views taken along the line F-F′ illustratingin the external perspective views.

FIG. 16 is a flowchart illustrating a three-dimensional forming methodaccording to a fourth embodiment.

FIGS. 17A and 17B are schematic plan views illustrating steps of thethree-dimensional forming method according to the fourth embodiment andare sectional views taken along the line G-G′ illustrating in theschematic plan views.

FIGS. 18C and 18D are schematic plan views illustrating steps of thethree-dimensional forming method according to the fourth embodiment andare sectional views taken along the line G-G′ illustrating in theschematic plan views.

FIG. 19A is a plan view illustrating a three-dimensional fabricatedobject according to a fifth embodiment and FIG. 19B is a sectional viewtaken along the line K-K′ illustrated in FIG. 19A.

FIG. 20 is a flowchart illustrating a three-dimensional forming methodaccording to the fifth embodiment.

FIGS. 21A to 21D are sectional views and plan views illustrating thethree-dimensional forming method according to the fifth embodiment.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

Hereinafter, embodiments of the invention will be described withreference to the drawings.

First Embodiment

FIG. 1 is a schematic diagram illustrating the configuration of athree-dimensional forming apparatus according to a first embodiment. Inthe present specification, “three-dimensional forming” refers to forminga so-called stereoscopically fabricated object and includes, forexample, forming a shape having a thickness even when the shape is aflat shape or a so-called two-dimensional shape.

A three-dimensional forming apparatus 1000 (hereinafter referred to as aforming apparatus 1000) illustrated in FIG. 1 includes a sinteringdevice 100 that forms a three-dimensional fabricated object and amaterial supply device 200 serving as a material supply unit thatsupplies the sintering device 100 with supply material 300 (hereinafterreferred to as a green sheet 300) called a so-called green sheet inwhich metal powder and a binder which are raw material of thethree-dimensional fabricated object are kneaded and formed to a sheetshape.

The material supply device 200 includes a supply base 210, a supplytable 220 that can be driven in the Z axis direction oriented in theillustrated gravity direction by a driving unit (not illustrated)included in the supply base 210, and a transfer device 230 that holdsone topmost stacked green sheet among a plurality of green sheets 300placed on the supply table 220 and transfers the green sheet to thesintering device 100.

The transfer device 230 includes a sheet holding unit 230 a that iscapable of holding the green sheet 300 and a supply driving unit 230 bthat moves the sheet holding unit 230 a to the supply table 220relatively in at least the X axis direction and the Y axis direction.The sheet holding unit 230 a includes a sheet adsorption unit 230 cserving as, for example, a unit capable of holding and detaching thegreen sheet 300 in depressurization and sucking manners, and thus thegreen sheet 300 can be adsorbed and held by the sheet adsorption unit230 c. The method of holding the green sheet 300 by the sheet adsorptionunit 230 c is not limited to the above-described method. For example,when a raw material metal is a magnetic material, the green sheet may bemechanically held using a magnetic-force adsorption method or the likeor pilot holes.

The sintering device 100 includes a base 110, a stage 120 that can bemoved in the illustrated X, Y, or Z direction or can be driven in arotational direction about the Z axis by a driving device 111 serving asa driving unit included in the base 110, and a head base supporting unit130 that has one end portion fixed to the base 110 and the other endportion holding and fixing a head base 150 in which a plurality ofenergy radiation units 140 are held. In the embodiment, a configurationin which the stage 120 is driven in the X, Y, or Z direction by thedriving device 111 will be described. However, the invention is notlimited thereto. The stage 120 and the head base 150 may be able to bedriven relatively in the X, Y, or Z direction.

The sintering device 100 includes, on the stage 120, a sample plate 121that has heat resistance property to protect the stage 120 against heatenergy radiated from an energy radiation unit to be described below. Thegreen sheets 300 transferred from the material supply device 200 arestacked to be disposed on the sample plate 121. The sintering device 100may include a press roller 170 that is driven to reciprocate in the Xaxis direction, in this example, while pressing the green sheet 300 ofthe topmost layer to closely adhere the green sheet 300 of animmediately below layer against the green sheet 300 transferred andstacked in the topmost layer. The press roller 170 preferably includes aunit that heats the green sheet 300 in order to improve the adhesionbetween the upper and lower green sheets 300.

The plurality of energy radiation units 140 held in the head base 150will be described as the energy radiation units 140 that radiate lasersas energy in the embodiment (hereinafter the energy radiation units 140are referred to as laser radiation units 140). By using a laser asenergy to be radiated, the radiation of the energy can be focused on asupply material which is a target, and thus a three-dimensionalfabricated object with good quality can be formed. For example, aradiated energy amount (power or a scanning speed) can be easilycontrolled according to a kind of sintered material, and thus thethree-dimensional fabricated object with desired quality can beobtained.

The forming apparatus 1000 includes a control unit 400 serving as acontrol unit that controls the stage 120, the supply table 220, thelaser radiation unit 140, and the transfer device 230 described abovebased on fabrication data of the three-dimensional fabricated objectoutput from, for example, a data output apparatus such as a personalcomputer (not illustrated). The control unit 400 includes a drivingcontrol unit of the stage 120, a driving control unit of the supplytable 220, a driving control unit of the laser radiation unit 140, and adriving control unit of the transfer device 230 and includes a controlunit that controls the driving control units such that these units aredriven in tandem, although not illustrated.

Signals for controlling movement start and stop, a movement direction, amovement amount, and a movement speed of the stage 120 or the supplytable 220 are generated in a stage controller 410 based on controlsignals from the control unit 400 by the driving device 111 included inthe base 110, and thus the stage 120 included to be movable with respectto the base 110 and the supply table 220 included to be movable to thesupply base 210 are sent to the driving device 111 included in the base110 or a driving device (not illustrated) included in the supply base210 to be driven.

Signals for controlling movement of the sheet holding unit 230 a by thesupply driving unit 230 b included in the transfer device 230 and theholding or detachment of the green sheet 300 to or from the sheetadsorption unit 230 c are generated based on control signals from thecontrol unit 400 in a material supply device controller 420, and thusthe transfer of the transfer device 230 included in the material supplydevice 200 transferred to the sintering device 100 of the green sheets300 is controlled.

In regard to the laser radiation unit 140 held in the head base 150,control signals are sent from the control unit 400 to a laser controller430 and output signals for causing one or all of the plurality of laserradiation units 140 to radiate lasers are sent from the laser controller430. The radiation of the lasers from the laser radiation units 140 iscontrolled such that the lasers are radiated to sinter-formed regionsobtained from shape data of a predetermined three-dimensional fabricatedobject in the green sheets 300 placed on the stage 120 insynchronization with driving signals of the stage 120 by the stagecontroller 410.

FIGS. 2A and 2B are diagrams illustrating an example of a holding formof the laser radiation units 140 included in a plurality of head units160 held in the head base 150. FIG. 2A is an external diagramillustrating the head base 150 in a direction indicated by an arrow Aillustrated in FIG. 1. FIG. 2B is a schematic sectional view taken alongthe line B-B′ illustrated in FIG. 2A.

As illustrated in FIG. 2A, the plurality of head units 160 are held inthe head base 150 included in the forming apparatus 1000 according tothe first embodiment. As illustrated in FIG. 2B, the head unit 160includes the laser radiation unit 140 and a holding tool 160 a thatholds the laser radiation unit 140 so that a laser outlet 140 a fromwhich a laser L of the laser radiation unit 140 exits is disposed towardthe green sheet 300 in the head base 150. The head unit 160 is fixed tothe head base 150 by a fastening unit (not illustrated) which can bedetachably mounted.

In the embodiment, six sets of head units 160 are fastened to the headbase 150. As illustrated in FIG. 2A, first head units 161 and 162,second head units 163 and 164, and third head units 165 and 166 in oneline of two sets are disposed in three lines from the lower side of thedrawing. As illustrated in FIG. 2B, sintered portions 310 with asintering width r are formed in the green sheet 300 by the lasers Lradiated from the laser radiation units 140, so that a part of theconfiguration of a three-dimensional fabricated object is formed as anaggregate of the sintered portions 310 formed by the lasers L radiatedfrom the laser radiation units 140 included in the plurality of headunits 161, 162, 163, 164, 165, and 166 held in the head base 150.

FIGS. 3A to 3E are plan views (in the direction indicated by the arrow Aillustrated in FIG. 1) conceptually illustrating a relation betweendisposition of the head units 160 and form shapes of the sinteredportions 310. First, as illustrated in FIG. 3A, the lasers L areradiated from the laser radiation units 140 of the head units 161 and162 at a sintering start point p1 of the green sheet 300, so thatsintered portions 310 a and 310 b are formed. To facilitate thedescription, the sintered portions 310 are hatched even in the planviews.

While the lasers L are radiated from the head units 161 and 162, thegreen sheet 300 is moved in the Y (+) direction relative to the headbase 150 up to a position at which the sintering start point p1illustrated in FIG. 3B corresponds to the second head units 163 and 164.Accordingly, the sintered portions 310 a and 310 b extend from thesintering start point p1 to a position p2 after the relative movement ofthe green sheet 300 so that the sintering width r is maintained.Further, the lasers L are radiated from the second head units 163 and164 corresponding to the sintering start point p1, so that sinteredportions 310 c and 310 d are formed.

The lasers L are radiated at the position at which the sintering startpoint p1 illustrated in FIG. 3B corresponds to the second head units 163and 164, so that the sintered portions 310 c and 310 d start to beformed. While the lasers L are radiated from the head units 163 and 164,the green sheet 300 is moved up to a position at which the sinteringstart point p1 illustrated in FIG. 3C corresponds to the third headunits 165 and 166 relative to the head base 150. Accordingly, thesintered portions 310 c and 310 d extend from the sintering start pointp1 to the position p2 after the relative movement of the green sheet 300so that the sintering width r is maintained. Simultaneously, thesintered portions 310 a and 310 b extend from the sintering start pointp1 to a position p3 after the relative movement of the green sheet 300so that the sintering width r is maintained. Further, the lasers L areradiated from the third head units 165 and 166 corresponding to thesintering start point p1, so that sintered portions 310 e and 310 f areformed.

The lasers L are radiated at the position at which the sintering startpoint p1 illustrated in FIG. 3C corresponds to the third head units 165and 166, so that the sintered portions 310 e and 310 f start to beformed. While the lasers L are radiated from the head units 165 and 166,the green sheet 300 is moved relative to the head base 150 so that thesintering start point p1 illustrated in FIG. 3D is further moved in theY (+) direction. Accordingly, the sintered portions 310 e and 310 fextend from the sintering start point p1 to the position p2 after therelative movement of the green sheet 300 so that the sintering width ris maintained. Simultaneously, the sintered portions 310 a and 310 bextend from the sintering start point p1 to a position p4 after therelative movement of the green sheet 300 and the sintered portions 310 cand 310 d extend from the sintering start point p1 to the position p3after the relative movement so that the sintering width r is maintained.

In a case in which the position p4 is set to a sintering end position(hereinafter the position p4 is referred to as the sintering end pointp4), the radiation of the lasers L from the head units 161 and 162 isstopped at the sintering end point p4 illustrated in FIG. 3D. Further,while the green sheet 300 is moved relatively in the Y (+) direction,the lasers L are radiated until the head units 163, 164, 165, and 166reach the sintering end point p4. As illustrated in FIG. 3E, thesintered portions 310 c, 310 d, 310 e, and 310 f are formed from thesintering start point p1 to the sintering end point p4 so that thesintering width r is maintained. In this way, by radiating the lasers Lsequentially from the head units 161, 162, 163, 164, 165, and 166 whilemoving the green sheet 300 from the sintering start point p1 to thesintering end point p4, it is possible to form the substantiallyrectangular sintered portions 310 with a width R and a length H in theexample of the embodiment.

As described above, the sintering device 100 included in the formingapparatus 1000 according to the first embodiment can form the sinteredportions 310 with a desired shape in the green sheet 300 by selectivelyradiating the lasers L from the head units 161, 162, 163, 164, 165, and166 in synchronization with the movement of the green sheet 300. Asdescribed above, by merely moving the green sheet 300 in one directionof the Y axis direction in the embodiment, it is possible to obtain thesintered portions 310 with a desired shape in a region with a width R×alength H illustrated in FIG. 3E. Thus, it is possible to obtain apartial fabricated object to be described below as an aggregate of thesintered portions 310.

The forming apparatus 1000 in which the green sheet 300 is supplied fromthe material supply device 200 to the sintering device 100 has beendescribed, but the invention is not limited thereto. For example, amaterial before sintering maybe supplied by supplying powder metal ontothe sample plate 121 and forming the powder metal with a desiredthickness by a squeegee.

Second Embodiment

FIGS. 4A and 4B are schematic diagram illustrating the configuration ofa three-dimensional forming apparatus according to a second embodiment.A three-dimensional forming apparatus 2000 (hereinafter referred to as aforming apparatus 2000) illustrated in FIG. 4A is different from theforming apparatus 1000 according to the first embodiment in theconfiguration of a material supply unit and the configuration of a headbase and head units. Accordingly, the same reference numerals are givento the same constituent elements as those of the forming apparatus 1000according to the first embodiment and the description thereof will beomitted.

As illustrated in FIGS. 4A and 4B, the forming apparatus 2000 includes abase 110, a stage 120 that can be moved in the illustrated X, Y, or Zdirection or can be driven in a rotational direction about the Z axis bya driving device 111 serving as a driving unit included in the base 110,and a head base supporting unit 130 that has one end portion fixed tothe base 110 and the other end portion holding and fixing a head base1100 in which a plurality of head units 1400 including an energyradiation unit 1300 and a material ejection unit 1230 are held.

In a process of forming a three-dimensional fabricated object 500,partial fabricated objects 501, 502, and 503 are formed on the stage 120in a layered state. In the forming of the three-dimensional fabricatedobjects 500, as will be described below, the sample plate 121 that hasheat resistance property may be used to protect against heat of thestage 120 so that the three-dimensional fabricated objects 500 areformed on the sample plate 121, since the heat energy is radiated fromthe laser. For example, a ceramic plate can be used as the sample plate121 to obtain the high heat resistance property, and further reactivitywith a sintered or melted supply material is low and thethree-dimensional fabricated objects 500 can be prevented fromdegrading. In FIG. 4A, to facilitate the description, three layers ofthe partial fabricated objects 501, 502, and 503 have been exemplified,but partial fabricated objects are stacked until the desired shapes ofthe three-dimensional fabricated objects 500 are obtained.

FIG. 4B is an enlarged view of a portion C indicating the head base 1100illustrated in FIG. 4A.

As illustrated in FIG. 4B, the head base 1100 holds a plurality of headunits 1400. As will be described below in detail, one head unit 1400 isconfigured such that a material ejection unit 1230 included in thematerial supply device 1200 serving as a material supply unit and anenergy radiation unit 1300 serving as an energy radiation unit are heldin a holding tool 1400 a. The material ejection unit 1230 includes anejection nozzle 1230 a and an ejection driving unit 1230 b that iscaused to eject a material from the ejection nozzle 1230 a by a materialsupply controller 1500.

The energy radiation unit 1300 will be described as the energy radiationunit 1300 radiating a laser as energy in the embodiment (hereinafter theenergy radiation unit 1300 is referred to as a laser radiation unit1300). The radiation of the energy can be focused on a supply materialwhich is a target, and thus a three-dimensional fabricated object withgood quality can be formed. For example, a radiated energy amount (poweror a scanning speed) can be easily controlled according to a kind ofsintered material, and thus the three-dimensional fabricated object withdesired quality can be obtained.

The material ejection unit 1230 is connected to a supply tube 1220 andthe material supply unit 1210 accommodating the supply materialcorresponding to each head unit 1400 held in the head base 1100. Apredetermined material is supplied from the material supply unit 1210 tothe material ejection units 1230. In the material supply unit 1210,material accommodation units 1210 a accommodate sintered materialsincluding the raw materials of the three-dimensional fabricated objects500 fabricated by the forming apparatus 2000 according to the embodimentas supply materials. The individual material accommodation units 1210 aare preferably connected to the individual material ejection units 1230by the supply tubes 1220. In this way, since the individual materialaccommodation units 1210 a are provided, a plurality of different kindsof sintered materials can be supplied from the head base 1100.

The sintered material which is the supply material is a mixed materialof a slurry state (or a paste form) obtained by kneading, for example,an elementary powder of metals such as magnesium (Mg), iron (Fe), cobalt(Co), chrome (Cr), aluminum (AL), titanium (Ti), and a nickel (Ni) whichare raw materials of the three-dimensional fabricated object 500, or amixed powder of an alloy including one or more of the metals with asolvent and a thickener serving as a binder.

As illustrated in FIG. 4A, the forming apparatus 2000 includes thecontrol unit 400 serving as a control unit controlling theabove-described stage 120, the material ejection units 1230 included inthe material supply device 1200, and the laser radiation units 1300based on fabrication data of the three-dimensional fabricated objects500 output from, for example, a data output apparatus such as a personalcomputer (not illustrated). Although not illustrated in the drawing, thecontrol unit 400 includes at least a driving control unit of the stage120, an operation control unit of the material ejection unit 1230, andan operation control unit of the laser radiation device 1300. Thecontrol unit 400 further includes a control unit that drives andoperates the stage 120, the material ejection unit 1230, and the laserradiation unit 1300 in tandem.

For the stage 120 included to be movable to the base 110, signals forcontrolling movement start or stop and a movement direction, a movementamount, a movement speed, or the like of the stage 120 are generated inthe stage controller 410 based on a control signal from the control unit400 and are sent to the driving device 111 included in the base 110, sothat the stage 120 is moved in the illustrated X, Y, or Z direction. Forthe material ejection unit 1230 included in the head unit 1400, a signalfor controlling a material ejection amount or the like from the ejectionnozzle 1230 a in the ejection driving unit 1230 b included in thematerial ejection unit 1230 is generated in a material supply controller440 based on a control signal from the control unit 400 and apredetermined amount of material is ejected from the ejection nozzle1230 a by the generated signal.

FIGS. 5 and 6 illustrate an example of the holding form of the pluralityof head units 1400 held in the head base 1100 and the laser radiationunits 1300 and the material ejection units 1230 held in the head units1400. FIG. 5 is an external diagram illustrating the head base 1100 in adirection indicated by an arrow D illustrated in FIG. 4B. FIG. 6 is aschematic sectional view taken along the line E-E′ illustrated in FIG.5.

As illustrated in FIG. 5, the plurality of head units 1400 are held byfixing units (not illustrated) in the head base 1100. The head base 1100of the forming apparatus 2000 according to the embodiment include thehead units 1400 of eight units, such as first head units 1401 and 1402,second head units 1403 and 1404, third head units 1405 and 1406, andfourth head units 1407 and 1408, from the lower side of the drawing.Although not illustrated, the material ejection unit 1230 included ineach of the head units 1401 to 1408 is linked to the material supplyunit 1210 via the ejection driving unit 1230 b by the supply tube 1220and the laser radiation unit 1300 is linked to the laser controller 430to be held in the holding tool 1400 a.

As illustrated in FIG. 6, the material ejection units 1230 ejectsintered materials M (hereinafter referred to as materials M) toward thesample plate 121 placed on the stage 120 from the ejection nozzle 1230a. In the head unit 1401, an ejection type in which the material M isejected in a liquid droplet form is exemplified. In the head unit 1402,an ejection type in which the material M is supplied in a continuousform is exemplified. The ejection type of the material M may be eitherthe liquid droplet form or the continuous form. In the embodiment, thematerial M is assumed to be ejected in the liquid droplet form in theembodiment.

The material M ejected in the liquid droplet form from the ejectionnozzle 1230 a flies substantially in the gravity direction to be landedon the sample plate 121. The laser radiation units 1300 are held in theholding tools 1400 a to have predetermined slopes with respect to thegravity direction so that the lasers L to be output are oriented tolanding positions of the materials M. Thus the lasers L are radiatedfrom the laser radiation units 1300 to the landed materials M and thematerials M are baked and sintered so that sintered portions 50 areformed. An aggregate of the sintered portions 50 is formed as a partialfabricated object of the three-dimensional fabricated object 500 formedon the sample plate 121, for example, the partial fabricated object 501(see FIGS. 4A and 4B).

FIGS. 7A to 9 are plan views (in the direction indicated by the arrow Dillustrated in FIG. 4B) conceptually illustrating a relation betweendisposition of the head units 1400 and form shapes of sintered portions50. First, as illustrated in FIG. 7A, the material M is ejected from theejection nozzles 1230 a of the head units 1401 and 1402 at a fabricationstart point q1 on the sample plate 121 and the lasers L are radiatedfrom the laser radiation units 1300 to the materials M landed to thesample plate 121, so that sintered portions 50 a and 50 b are formed. Tofacilitate the description, the sintered portions 50 are hatched even inthe plan views. The first partial fabricated object 501 formed on theupper surface of the sample plate 121 will be exemplified in thedescription.

First, as illustrated in FIG. 7A, the materials M are ejected from thematerial ejection units 1230 included in the first head units 1401 and1402 illustrated on the lower side at the fabrication start point q1 ofthe partial fabricated object 501 on the sample plate 121. The lasers Lare radiated from the laser radiation units 1300 included in the headunits 1401 and 1402 to the ejected materials M, so that the sinteredportions 50 a and 50 b are formed.

While the materials M are continuously ejected from the materialejection units 1230 of the head units 1401 and 1402 and the lasers L arecontinuously radiated from the laser radiation units 1300, the sampleplate 121 is moved in the Y (+) direction relative to the head base 1100up to a position at which the fabrication start point q1 illustrated inFIG. 7B corresponds to the second head units 1403 and 1404. Accordingly,the sintered portions 50 a and 50 b extend from the fabrication startpoint q1 to a position q2 after the relative movement of the sampleplate 121 so that the sintering width t is maintained. Further, thematerials M are ejected from the second head units 1403 and 1404corresponding to the fabrication start point q1 and the lasers L areradiated to the materials M, so that sintered portions 50 c and 50 dstart to be formed.

The sintered portions 50 c and 50 d illustrated in FIG. 7B start to beformed, and while the materials M are continuously ejected from thematerial ejection units 1230 of the head units 1403 and 1404, and thelasers L are continuously radiated from the laser radiation units 1300,the sample plate 121 is moved in the Y (+) direction relative to thehead base 1100 up to a position at which the fabrication start point q1illustrated in FIG. 7C corresponds to the third head units 1405 and1406. Accordingly, the sintered portions 50 c and 50 d extend from thefabrication start point q1 to the position q2 after the relativemovement of the sample plate 121 so that the sintering width t ismaintained. Simultaneously, the sintered portions 50 a and 50 b extendfrom the fabrication start point q1 to a position q3 after the relativemovement of the sample plate 121 so that the sintering width t ismaintained. The materials M are ejected from the third head units 1405and 1406 corresponding to the fabrication start point q1 and the lasersL are radiated to the materials M, so that sintered portions 50 e and 50f start to be formed.

The sintered portions 50 e and 50 f illustrated in FIG. 7C start to beformed, and while the materials M are continuously ejected from thematerial ejection units 1230 of the head units 1405 and 1406, and thelasers L are continuously radiated from the laser radiation units 1300,the sample plate 121 is moved in the Y (+) direction relative to thehead base 1100 up to a position at which the fabrication start point q1illustrated in FIG. 8D corresponds to the fourth head units 1407 and1408. Accordingly, the sintered portions 50 e and 50 f extend from thefabrication start point q1 to the position q2 after the relativemovement of the sample plate 121 so that the sintering width t ismaintained. Simultaneously, the sintered portions 50 a and 50 b extendfrom the fabrication start point q1 to a position q4 after the relativemovement of the sample plate 121 and the sintered portions 50 c and 50 dextend from the fabrication start point q1 to the position q3 after therelative movement of the sample plate 121 so that the sintering width tis maintained. The materials M are ejected from the fourth head units1407 and 1408 corresponding to the fabrication start point q1 and thelasers L are radiated to the materials M, so that sintered portions 50 gand 50 h start to be formed.

In a case in which the position q5 is set to a sintering end position(hereinafter the position q5 is referred to as the fabrication end pointq5), as illustrated in FIG. 8E, the sample plate 121 is relatively moveduntil the head units 1401 and 1402 reach the fabrication end point q5,so that the sintered portions 50 g and 50 h extend. In the head units1401 and 1402 reaching the fabrication end point q5, the ejection of thematerials M from the material ejection units 1230 included in the headunits 1401 and 1402 and the radiation of the lasers L from the laserradiation units 1300 are stopped. Further, while the sample plate 121 isrelatively moved in the Y (+) direction, the lasers L are radiated untilthe head units 1403, 1404, 1405, 1406, 1407, and 1408 reach thefabrication end point q5. Thus the sintered portions 50 a, 50 b, 50 c,50 d, 50 e, 50 f, 50 g, and 50 h are formed from the fabrication startpoint q1 to the fabrication end point q5 so that the sintering width tis maintained, as illustrated in FIG. 9. In this way, while the sampleplate 121 is moved from the fabrication start point q1 to thefabrication end point q5, the materials M are ejected and supplied andthe lasers L are radiated sequentially from the head units 1401, 1402,1403, 1404, 1405, 1406, 1407, and 1408, so that the substantiallyrectangular sintered portions 50 with a width T and a length J can beformed in the example of the embodiment. Accordingly, the partialfabricated object 501 of the first layer can be formed and configured asthe aggregate of the sintered portions 50.

As described above, the forming apparatus 2000 according to the secondembodiment selectively performs the ejection and supply of the materialsM from the material ejection units 1230 included in the head units 1401,1402, 1403, 1404, 1405, 1406, 1407, and 1408 and the radiation of thelasers L from the laser radiation units 1300 in synchronization with themovement of the stage 120 including the sample plate 121, so that thepartial fabricated object 501 with a desired shape can be formed on thesample plate 121. As described above, by merely moving the stage 120 inone direction of the Y axis direction in this example when the stage 120is moved, it is possible to obtain the sintered portions 50 with thedesired shape in a region with the width T x the length J illustrated inFIG. 9 and the partial fabricated object 501 as the aggregate of thesintered portions 50.

As the materials M ejected from the material ejection units 1230,different materials from the head units can also be ejected and suppliedfrom one unit or two or more units of the head units 1401, 1402, 1403,1404, 1405, 1406, 1407, and 1408. Accordingly, the forming apparatus2000 according to the embodiment can be used to obtain thethree-dimensional fabricated objects including composite partialfabricated objects formed from different kinds of materials.

The number and arrangement of the head units 160 disposed in the headbase 150 included in the forming apparatus 1000 according to theabove-described first embodiment or the number and arrangement of thehead units 1400 disposed in the head base 1100 included in the formingapparatus 2000 according to the second embodiment are not limited to theabove-described number and arrangement illustrated in FIGS. 2A and 2B orFIG. 5. FIGS. 10A and 10B schematically illustrate examples of otherdispositions of the head units 160 or 1400 disposed in the head base 150or 1100.

FIG. 10A illustrates a form in which the plurality of head units 160 or1400 are arranged in a line in the X axis direction in the head base 150or 1100. FIG. 10B illustrates a form in which the head units 160 or 1400are arranged in a lattice form in the head base 150 or 1100. The numberof head units arranged in either example is not limited to theillustrated example.

Third Embodiment

A three-dimensional forming method of forming a three-dimensionalfabricated object using the three-dimensional forming apparatus 1000according to the first embodiment will be described according to a thirdembodiment. FIG. 11 is a flowchart illustrating the three-dimensionalforming method according to the third embodiment. FIG. 12 is a schematicdiagram illustrating the configuration of a green sheet formingapparatus that forms the green sheet 300. FIGS. 13A, 13B, 14A, and 14Bare schematic plan views and sectional views illustrating steps of thethree-dimensional forming method according to the embodiment. FIGS. 15Eand 15F are external perspective views and schematic sectional viewsillustrating steps of the three-dimensional forming method according tothe embodiment.

Three-Dimensional Fabrication Data Acquisition Process

As illustrated in FIG. 11, in the three-dimensional forming methodaccording to the embodiment, a three-dimensional fabrication dataacquisition process (S1) of acquiring three-dimensional fabrication dataof the three-dimensional fabricated object from, for example, a personalcomputer (not illustrated) by the control unit 400 (see FIG. 1) isperformed. As the three-dimensional fabrication data acquired in thethree-dimensional fabrication data acquisition process (S1), controldata is transmitted from the control unit 400 to the stage controller410, the material supply device controller 420, and the laser controller430, and then the process proceeds to a material preparation process.

Material Preparation Process

In a material preparation process (S2), a predetermined number of greensheets 300 are placed on the supply table 220 included in the materialsupply device 200. The green sheets 300 are formed by a green sheetforming apparatus 3000 or the like of the green sheets 300, as aschematic configuration is exemplified in FIG. 12.

As illustrated in FIG. 12, the green sheet forming device 3000 includesa raw material supply unit 3100 that supplies a material M and atransfer belt 3200 that receives the material M discharged from the rawmaterial supply unit 3100 and transfers the material M. A mixture inwhich a metal powder formed with a size equal to or less than 30 μm anda binder are kneaded and formed in a paste form is used as the materialM. As the metal powder, for example, an alloy such as a cobalt-basedalloy, maraging steel, stainless steel, a titanium-based alloy, anickel-based alloy, a magnesium alloy, or a copper-based alloy, or ametal such as iron, titanium, nickel, or copper can be used. As thebinder, a thermoplastic resin or a thermoplastic water-soluble resin canbe used. As the thermoplastic resin, for example, polylactic acid (PLA),polypropylene (PP), polyphenylene sulfide (PPS), polyamide (PA), ABS, orpolyether ether ketone (PEEK) is used. As the thermoplasticwater-soluble resin, for example, polyvinyl alcohol (PVA) or polyvinylebutyral (PVB) is used.

The material M in which the above-described metal powder and binder anda solvent for viscosity adjustment are added and kneaded is input to theraw material supply unit 3100, and a predetermined amount of material Mis sequentially discharged to the transfer belt 3200 driven in anillustrated arrow α direction. With the movement of the transfer belt3200 in the α direction, the thickness of the material M is equalized byan equalizing roll 3300, the material M passes through a subsequentpressurization roller 3400 so that the material M has a predeterminedthickness for the green sheet 300. Then, the material M is cut out in apredetermined length by a cutting unit 3500 to obtain the green sheet300.

Material Supply Process

When the predetermined number of green sheets 300 are placed on thesupply table 220 of the material supply device 200 in the materialpreparation process (S2), a material supply process (S3) starts. In thematerial supply process (S3), the material supply device controller 420generates a driving signal of the transfer device 230 based on a controlsignal from the control unit 400 and drives the transfer device 230.

First, the sheet holding unit 230 a is moved up to a predeterminedposition, and the uppermost sheet of the green sheets 300 stacked on thesupply table 220 is adsorbed and held by the sheet adsorption unit 230c. The sheet holding unit 230 a is moved to the sample plate 121 of thesintering device 100 while holding the green sheet 300, the green sheet300 is detached and separated from the sheet adsorption unit 230 c, andthe green sheet 300 is placed on the sample plate 121. After the greensheet 300 is placed and separated, the sheet holding unit 230 a returnsto a standby position of the material supply device 200. Hereinafter,the green sheet 300 placed as a first layer will be described as a firstlayer green sheet 301.

Sintering Process

The process proceeds to a sintering process (S4) in which the lasers Lare radiated from the laser radiation units 140 included in theplurality of head units 160 held in the head base 150 to the green sheet301 of the first layer placed on the sample plate 121 in the materialsupply process (S3).

The sintering in the sintering process (S4) is a process of removing thebinder from the state in which the metal powder and the binder includedin the green sheet 300 are included, bonding the metal powder, andforming a metal fabricated object.

In FIGS. 13A, 13B, and 14A, a method of forming a sintered portion 311of the green sheet 301 of the first layer in the sintering process (S3)is illustrated. In this example, a method of forming the partialfabricated object 501 of the first layer in a circular state included inthe three-dimensional fabricated object 500 is exemplified. In FIGS. 13Ato 14B, plan views are illustrated on the upper sides and sectionalviews taken along the line F-F′ illustrated in the plan views on thelower sides.

As illustrated in FIG. 13A, while moving the head base 150 in the Ydirection relative to the green sheet 301 of the first layer placed onthe sample plate 121 included on the stage 120, the lasers L areradiated toward the green sheet 301 from the laser radiation units 140included in the head units 160 (not illustrated in the drawing) disposedin the head base 150.

When the relative movement of the head base 150 by a predeterminedamount ends, sintered portions 310 are formed as a aggregate of thesintered portions corresponding to the sintered portions 310 a, 310 b,310 c, 310 d, 310 e, and 310 f formed at the time of the radiation fromthe laser radiation units 140, as described in FIG. 3D, so that thefirst sintered portion 311 included in the partial fabricated object 501is formed. As illustrated in FIG. 13B, the head base 150 forms theaggregate of the sintered portions corresponding to the sinteredportions 310 a, 310 b, 310 c, 310 d, 310 e, and 310 f formed at the timeof the radiation from the laser radiation units 140, as described inFIG. 3D, to be continuous with the sintered portions 310 illustrated inFIGS. 13A, so that a sintered portion 312 is formed and thus a sinteredportion 310 joined to the sintered portion 311 is formed.

As illustrated in FIG. 13B, the head base 150 forms the aggregate of thesintered portions corresponding to the sintered portions 310 a, 310 b,310 c, 310 d, 310 e, and 310 f formed at the time of the radiation fromthe laser radiation units 140, as described in FIG. 3D, to be continuouswith the sintered portions 310 illustrated in FIG. 13A a predeterminednumber of times repeatedly in sequence. Then, as illustrated in FIG.14C, an i-th sintered portion 31 i in which the sintered portion 310 isformed until the shape of the partial fabricated object 501 is formed,and thus the partial fabricated object 501 and a portion excluding thepartial fabricated object 501, that is, an unsintered portion 301 a, areformed in the green sheet 301 of the first layer.

In this way, the sintered partial fabricated object 501 and theunsintered portion 301 a are formed in the sintering process (S4), sothat a first layer 301 b is formed as a first single layer. Theabove-described series of processes from the material supply process(S3) and the sintering process (S4) is a single layer forming process(S100). Then, the sintering process (S4) ends, that is, the single layerforming process (S100) ends and the process proceeds to a subsequentstack number comparison process.

Stack Number Comparison Process

When the first layer 301 b including the partial fabricated object 501which is the first layer, the unsintered portion 301 a is formed in thesingle layer forming process (S100), the process proceeds to a stacknumber comparison process (S5) of performing comparison with fabricationdata obtained in the three-dimensional fabrication data acquisitionprocess (S1). In the stack number comparison process (S5), a stacknumber N of green sheets 300 in which partial fabricated objects areformed and which are necessary to form the three-dimensional fabricatedobject 500 is compared to a stack number n of green sheets 300 stackedup to the single layer forming process (S100) immediately before thestack number comparison process (S5). When n<N is determined in thestack number comparison process (S5), the process proceeds to a stackingprocess of performing the single layer forming process (S100) again.

Stacking Process

A stacking process (S6) is an instruction process of performing thesingle layer forming process (S100) again when n<N is determined in thestack number comparison process (S5). The material supply process (S3)which is a start process of the single layer forming process (S100) isperformed.

As illustrated in FIG. 14D, the green sheet 300 is supplied to be placedon the upper portion of the first layer 301 b through the stackingprocess (S6) and becomes a green sheet 302 of a second layer. Then, asillustrated in FIGS. 13A, 13B, and FIG. 14D, the sintering process (S5)is performed on the green sheet 302 of the second layer, so that asecond layer 302 b can be obtained as a second single layer in which apartial fabricated object 502 of the second layer and a unsinteredportion (not illustrated) are formed. Thereafter, the process proceedsto the stack number comparison process (S6). When n<N is determined, thestacking process (S6) starts again. The stacking process (S6) and thesingle layer forming process (S100) are repeated until n=N is determinedin the stack number comparison process (S5).

As illustrated in FIG. 15E, when the predetermined stack number N isstacked, the three-dimensional fabricated object 500 is formed on thesample plate 121. Unsintered portions 300 a stacked to be formed fromthe first layer 301 b to an N-th layer 30Nb are also formed on thesample plate 121. Then, when n=N is determined in the stack numbercomparison process (S5), the process proceeds to an unsintered portionremoval process.

Unsintered Portion Removal Process

An unsintered portion removal process (S7) is a process of removingportions excluding the three-dimensional fabricated object 500, that is,the unsintered portions 300 a. As the method of removing the unsinteredportions 300 a, for example, a mechanical removal method or a method ofdissolving the binder including the unsintered portions 300 a using asolvent and removing the remaining metal powder can be applied. In theembodiment, the mechanical removal method will be described as anexample.

As illustrated in FIG. 15F, in the unsintered portion removal process(S7), the unsintered portions 300 a are removed on the sample plate 121by striking the unsintered portions 300 a with a removal tool 600 with awedge-shaped tip end and breaking the unsintered portions 300 a. Then,the three-dimensional fabricated object 500 remains on the sample plate121 and is extracted. In the embodiment, the case in which theunsintered portion removal process (S7) is performed on the sample plate121 has been described, but the unsintered portion removal process maybe performed on a separately provided work stand.

In the three-dimensional forming method for the three-dimensionalfabricated object 500 according to the above-described third embodiment,in the sintering process (S5) of the single layer forming process(S100), the sintered portions 310 can be formed in a broad region merelymoving the head base 150 relative to the stage 120 in one direction, inthis example, the Y axis direction since the plurality of head units 160including the laser radiation units 140 are included in the head base150 included in the sintering device 100. Thus, it is possible to obtainthe three-dimensional forming method with high productivity.

Fourth Embodiment

A three-dimensional forming method of forming a three-dimensionalfabricated object using the three-dimensional forming apparatus 2000according to the second embodiment will be described according to afourth embodiment. FIG. 16 is a flowchart illustrating thethree-dimensional forming method according to the fourth embodiment.FIGS. 17A, 17B, 18A, and 18B are diagrams illustrating athree-dimensional forming process according to the embodiment andschematic plan views on the upper sides and schematic sectional viewstaken along the line G-G′ illustrating the schematic plan views on thelower sides.

Three-Dimensional Fabrication Data Acquisition Process

As illustrated in FIG. 16, in the three-dimensional forming methodaccording to the embodiment, a three-dimensional fabrication dataacquisition process (S10) of acquiring three-dimensional fabricationdata of the three-dimensional fabricated object 500 from, for example, apersonal computer (not illustrated) by the control unit 400 (see FIGS.4A and 4B) is performed. As the three-dimensional fabrication dataacquired in the three-dimensional fabrication data acquisition process(S10), control data is transmitted from the control unit 400 to thestage controller 410, the material supply controller 1500, and the lasercontroller 430, and then the process proceeds to a single layer formingprocess.

Single Layer Forming Process

In a single layer forming process (S110), a material supply process(S20) and a sintering process (S30) are performed over a region in whichthe partial fabricated object 501 of the first layer is formed. In thematerial supply process (S20), the materials M are ejected in the liquiddroplet form toward the sample plate 121 from the material ejectionunits 1230 held in the plurality of head units 1400 included in the headbase 1100, and thus the materials M are landed to a predeterminedformation region on the sample plate 121.

When the materials M are landed to be formed on the sample plate 121 inthe material supply process (S20), the process proceeds to the sinteringprocess (S30). In the sintering process (S30), the lasers L are radiatedfrom the laser radiation units 1300 held by the head units 1400 to thematerials M supplied in the liquid droplet form in the material supplyprocess (S20), and thus the materials M are baked and sintered so thatsintered portions 50 are formed.

As described in FIG. 9, the head units 1401, 1402, 1403, 1404, 1405,1406, 1407, and 1408 form the aggregate of the sintered portionscorresponding to the sintered portions 50 a, 50 b, 50 c, 50 d, 50 e, 50f, 50 g, and 50 h by moving the head base 1100 in the Y axis directionrelative to the stage 120 on which the sample plate 121 is placed whilerepeating the material supply process (S20) and the sintering process(S30) in a predetermined region, and thus the initial sintered portions50 of the partial fabricated object 501 are formed as a sintered portion511.

Further, as illustrated in FIG. 17B, the head base 1100 is moved in theX axis direction relative to the stage 120 at a position at which thesintered portions corresponding to the sintered portions 50 a, 50 b, 50c, 50 d, 50 e, 50 f, 50 g, and 50 h are formed to be continuous with thesintered portion 511 illustrated in FIG. 17A. The head units 1401, 1402,1403, 1404, 1405, 1406, 1407, and 1408 form the aggregate of thesintered portions corresponding to the sintered portions 50 a, 50 b, 50c, 50 d, 50 e, 50 f, 50 g, and 50 h by moving the head base 1100 in theY axis direction relative to the stage 120 on which the sample plate 121is placed while repeating the material supply process (S20) and thesintering process (S30) in a predetermined region, and thus the sinteredportions 50 are formed as a sintered portion 512 continuous with thesintered portion 511. That is, the sintered portions 50 are formed bythe sintered portions 511 and 512.

As illustrated in FIG. 17B described above, sintered portions aresequentially formed to be continuous with the sintered portion 512 sothat the sintered portion 512 is formed to be continuous with theearlier formed sintered portion 511. As illustrated in FIG. 18C, an i-thsintered portion 51 i in which the sintered portion 50 is formed untilthe shape of the partial fabricated object 501 is formed, and thus thepartial fabricated object 501 of the first layer of thethree-dimensional fabricated object 500 is formed on the sample plate121.

As described above, in the embodiment, when the partial fabricatedobject 501 of the first layer is formed repeating the material supplyprocess (S20) and the sintering process (S30) while moving the head base1100 in the Y axis direction and the X axis direction relative to thesample plate 121, the single layer forming process (S110) ends. Then,the process proceeds to a subsequent stack number comparison process.

Stack Number Comparison Process

When the partial fabricated object 501 which is the first layer isformed as a first single layer in the single layer forming process(S110), the process proceeds to a stack number comparison process (S40)of performing comparison with fabrication data obtained in thethree-dimensional fabrication data acquisition process (S10). In thestack number comparison process (S40), a stack number N of partialfabricated objects included in the three-dimensional fabricated object500 is compared to a stack number n of partial fabricated objectsstacked up to the single layer forming process (S110) immediately beforethe stack number comparison process (S40). When n<N is determined in thestack number comparison process (S40), the process proceeds to astacking process of performing the single layer forming process (S110)again.

In the stack number comparison process (S40) after the partialfabricated object 501 of the first layer is formed as the first singlelayer illustrated in FIG. 18C, when the stack number n=1 and thethree-dimensional fabricated object 500 includes the stack number N ofpartial fabricated objects >1, n<N is determined and the processproceeds to s stacking process.

Stacking Process

A stacking process (S50) is an instruction process of performing thesingle layer forming process (S110) again when n<N is determined in thestack number comparison process (S40). When the process proceeds to thesingle layer forming process (S110), as illustrated in FIG. 18D, thehead base 1100 and the stage 120 are driven to start forming the partialfabricated object 502 on the upper portion of the partial fabricatedobject 501 of the first layer in the stacking process (S50) at aposition at which the material supply process (S20) and the sinteringprocess (S30) start based on the three-dimensional fabrication datacorresponding to the partial fabricated object 502 of the second layerwhich is the second single layer.

When the forming of the partial fabricated object 502 of the secondlayer ends, the process proceeds to the stack number comparison process(S40) again. Until n=N, the process proceeds to the stacking process(S50) and the single layer forming process (S110) is repeated to formthe three-dimensional fabricated object 500.

In the three-dimensional forming method for the three-dimensionalfabricated object 500 according to the above-described fourthembodiment, in the material supply process (S20) and the sinteringprocess (S30) of the single layer forming process (S110), the sinteredportions 50 can be formed in a broad region merely moving the head base1100 relative to the stage 120 in one direction, in this example, the Yaxis direction since the plurality of head units 1400 including thematerial ejection units 1230 and the laser radiation units 1300 areincluded in the head base 1100 included in the forming apparatus 2000.Thus, it is possible to obtain the three-dimensional forming method withhigh productivity.

Since the plurality of different kinds of sintered materials areaccommodated in the material accommodation units 1210 a in the materialsupply unit 1210 included in the forming apparatus 2000 illustrated inFIGS. 4A and 4B, the three-dimensional fabricated object 500 formed ofdifferent kinds of materials can be easily obtained.

Fifth Embodiment

A three-dimensional forming method according to a fifth embodiment willbe described. In the three-dimensional forming method according to theabove-described fourth embodiment, when the three-dimensional fabricatedobject has an overhang, there is no partial fabricated object of thelower layer to which the materials M ejected from the material ejectionunits 1230 are to be landed in the overhang, and thus the materials Mare not formed in the material supply process (S20) of theabove-described single layer forming process (S110) (see FIG. 18D). Whena region in which the partial fabricated object 501 of the first layerwhich is the partial fabricated object of the lower layer illustrated inFIG. 18D is not disposed in the fabrication region of the partialfabricated object 502 of the second layer is present, there is a concernof the partial fabricated object 502 being deformed and hanging down inthe gravity direction in the portion. That is, the material M before thesintering is a material in a slurry state (or a paste form) obtained bykneading an elementary powder of a metal which is the raw material, forexample, an alloy of stainless steel and titanium, or a mixed powder ofstainless steel and copper (Cu) which are difficult to alloy, an alloyof stainless and titanium, or a titanium alloy and cobalt (Co) or chrome(Cr) with a solvent and a thickener.

Accordingly, a method of forming a three-dimensional fabricated objectwithout deforming an overhang by the three-dimensional forming methodaccording to the fifth embodiment will be described. The same referencenumerals are given to the same processes as those of thethree-dimensional forming method according to the fourth embodiment, andthe description thereof will be omitted. To facilitate the description,as illustrated in the external plan view of FIG. 19A and the sectionalview of FIG. 19B taken along the line K-K′ illustrated in FIG. 19A, athree-dimensional fabricated object 700 with a simple shape will beexemplified to describe the three-dimensional forming method accordingto the fifth embodiment, but the invention is not limited to this shape.The invention can be applied when a fabricated object has a so-calledoverhang.

As illustrated in FIGS. 19A and 19B, the three-dimensional fabricatedobject 700 includes a flange portion 700 c which is an overhangextending to the outer side of a base portion 700 b in an concaveopening-side end of the columnar base portion 700 b including a concaveportion 700 a. To form the three-dimensional fabricated object 700 basedon the three-dimensional forming method according to the fifthembodiment, fabrication data for which support portions 710 to beremoved in a forming process reach the bottom portion of the baseportion 700 b in the illustrated lower direction of the flange portion700 c is added to three-dimensional fabrication data of thethree-dimensional fabricated object 700 for generation.

FIG. 20 is a flowchart illustrating a method of forming thethree-dimensional fabricated object 700 illustrated in FIGS. 19A and19B. FIGS. 21A to 21D illustrate a method of forming thethree-dimensional fabricated object 700 in the flowchart illustrated inFIG. 20, and partial sectional views and external plan views areillustrated on the left side and the right side of the drawings,respectively. In the three-dimensional fabricated object 700 accordingto the embodiment, an example in which four layers are stacked andformed will be described, but the invention is not limited thereto.

As illustrated in FIG. 21A, first, a partial fabricated object 701 whichis a first layer is formed on the sample plate 121 (not illustrated) bythe three-dimensional forming method according to the fourth embodiment.In the process of forming the partial fabricated object 701, partialsupport portions 711 of the first layer are also formed. The sinteringprocess (S30) of the single layer forming process (S110) described withreference to FIGS. 17A to 18B is not performed on the partial supportportions 711, and the single layer forming process (S110) is performedwith the material M remaining, that is, unsintered or unmelted.

Subsequently, the single layer forming process (S110) is repeated toform partial fabricated objects 702 and 703 which are second and thirdlayers, as illustrated in FIG. 21B. Then, in a process of forming thepartial fabricated objects 702 and 703, partial support portions 712 and713 of the second and third layers are also formed. As in the partialsupport portion 711, the sintering process (S30) of the single layerforming process (S110) is not performed on the partial support portions712 and 713, and the single layer forming process (S110) is performedwith the material M remaining, that is, unsintered or unmelted, so thatthe support portions 710 are formed by the partial support portions 711,712, and 713.

Next, as illustrated in FIG. 21C, a partial fabricated object 704 of afourth layer formed in the flange portion 700 c is formed. The partialfabricated object 704 is formed to be supported by ends 710 a of thesupport portions 710 formed by the partial support portions 711, 712,and 713. By forming the partial fabricated object 704 in this way, theends 710 a are formed as surfaces to which the material M (see FIG. 18D)is landed, so that the partial fabricated object 704 of the fourth layerwhich becomes the flange portion 700 c can be formed accurately.

Then, as illustrated in FIG. 21D, when the three-dimensional fabricatedobject 700 is fabricated, the support portions 710 are removed from thethree-dimensional fabricated object 700 in the support portion removalprocess (S60). Since the support portions 710 are formed of an unbakedmaterial, the support portions 710 can be physically cut by, forexample, a sharp-edged tool 800 which is a removal unit for the supportportions 710 in a support portion removal process (S60), as illustratedin FIG. 21D. Alternatively, the three-dimensional fabricated object 700may be removed by performing immersing in a solvent and dissolving thethickener included in the material.

As described above, when the three-dimensional fabricated object 700including the flange portion 700 c which is the overhang is formed, itis possible to prevent the flange portion 700 c from being deformed inthe gravity direction by forming the support portions 710 supporting theflange portion 700 c in conjunction with the forming of thethree-dimensional fabricated object 700. The support portions 710illustrated in FIGS. 21A and 21D are not limited to the form in whichthe illustrated flange portion 700 c is supported (sustained) on theentire surface, but the shapes, sizes, and the like of the supportportions are set according to the shape of the fabricated object, amaterial composition, or the like.

The specific configurations in the embodiments of the invention can beappropriately changed to other devices or methods within the scope ofthe invention in which the object of the invention can be achieved.

What is claimed is:
 1. A three-dimensional forming method comprising: afirst step of forming a sheet of material by supplying a first materialcontaining a metal powder onto a first stage and pressurizing the firstmaterial supplied onto the first stage, a second step of moving thesheet of material from the first stage to a second stage different fromthe first stage, a third step of curing a predetermined area of thesheet of material transferred to the second stage, a fourth step ofrepeatedly performing the first step, the second step, and the thirdstep to form a laminate.
 2. The three-dimensional forming methodaccording to claim 1 comprising, a fifth step of removing an uncuredportion from the laminate.
 3. The three-dimensional forming methodaccording to claim 1, wherein in the first step, the pressurized firstmaterial is cut to a predetermined length to form the sheet of material.4. The three-dimensional forming method according to claim 1, whereinthe first material includes a binder.
 5. The three-dimensional formingmethod according to claim 1, further comprising, in the first step,pressurizing the first material supplied onto the first stage by aroller to form the sheet of material.
 6. The three-dimensional formingmethod according to claim 5, wherein the roller presses the supplied thefirst material twice to form the sheet material.
 7. A three-dimensionalforming apparatus comprising, a first stage; a second stage differentfrom the first stage; a material supply unit that supplies a firstmaterial containing a metal powder onto the first stage; a pressurizingunit configured to pressurize the first material supplied onto the firststage to form a sheet of material; a moving unit configured to move thesheet of material from the first stage to the second stage; and a curingunit configured to cure a predetermined region of the sheet of material.